Doing this I get a nice flat Tin. Now I'm exporting the Tin with 3D -> VRML where I select the options:Indent text [check]visible layers [check]GeoVRML [no check]Center [no check]ElevationGrid [check]JPEG Quality = high

The resulting VRML (attached as unbenannt.rar) is incomplete. freeWRL is giving me the following error code: